1. Field of the Invention
This invention relates to a punching device of the sub-press type for use in a punch press, press brake or the like.
2. Prior Art
It is desirable and necessary to have an air gap between a retracted punch-guide-and-stripper-assembly and die which is larger than the maximum thickness of material that the punching device can perforate. Where the device is one that is considered to be of the heavy duty type, there is thus provided a substantial gap to accommodate such a workpiece. However, such punching device is also capable of handling thinner workpieces. When a relatively thin workpiece is placed on such a die for punching, there is a considerable air gap between the top surface of the workpiece and the punch and stripper assembly, an air gap which is considered excessive for operator safety. Thus, when punching thinner workpieces, it has been necessary to provide a suitable guard for operator safety or to use punching equipment having less capacity so that a smaller gap can be initially provided. Neither of these alternatives is attractive, efficient, or inexpensive.